The most conventional solutions are three bars turnstiles controlled by the reading of a valid transport ticket.
Low gates with mobile, sliding, revolving or swinging glass flaps are also known.
The main drawbacks of these known solutions are the following:
The speed of release of passage is very slow with these different systems as the masses in movement are considerable and the inertia to be overcome is high.
In the case of three bars turnstiles, the turnstile is moved manually and the bars of the turnstile permanently obstruct the passage, annoying passengers, in particular if they have luggage.
In revolving-gate systems, the gate occupies a large space which cannot be used for detection equipment.
The systems with a glass obstacle are fragile i.e. they cannot withstand impacts.
Current systems have a low reliability level as the obstacle can inhibit detection of the user's advance. It is difficult to carry out passage detection at different heights.
The fact that the ticket is recovered before passing the obstacle does not guarantee that the person has actually passed through.
Moreover, this recovery does not invite the person to pass through, as the turnstile remains static unless the person makes a movement to open it himself.